Documentation: Side effects of org-entry-properties and others

[D <d.williams@posteo.net>]

Hi,

it seems a few functions meant to expose org internals to programmers
seem to cause undocumented side effects.  A particular example being
org-entry-properties.  When called, it changes the match-data.  This can
cause issues in cases where leaking match-data can cause font-lock to
behave inconsistently or throw errors.  I think it would be a good idea
to add a prominent warning to such interfacing functions, or document it
somewhere in the module.

The same is true for org-element-lineage, but I am not so sure whether
it is intended for hacking purposes as much as org-entry-properties.
Sadly, I have no overview over the scope of this issue, so I do not know
whether my suggestion is unrealistic (for example, because it would mean
adding warnings practically everywhere).

Regards,

D.